OK this movie was made in the 80s or 90s it has 4 little green men it starts by them crash landing in a corn silo and a cop is sitting on the side of the road with radar and the speed say like 20000 miles and hr or something then later they get mistaken for trick or treaters and the kids try to help them get off our planet before the flying mechancle alien kills them theirs an old guy with a dog that tries to get pics of them and he eats dog treats with his dogs later the corn silo fills with popcorn because of the heat from when the take off from the planet can anyone remember the name of this movie?

Might be Spaced Invaders (1990) (http://www.imdb.com/title/tt0100666/)